As is well known to those skilled in the art, zeolite catalysts have been used in hydrocarbon processing. Prior art zeolites have been found to be effective as catalysts for cracking, hydrocracking, hydrosulfurization, etc. Recent trends in resid hydroprocessing demand increased conversion of feed having a boiling point above 1000.degree. F. as well as improved hydrogenation selectivity as measured by Conradson carbon conversion and hydrodenitrogenation (HDN) of the 1000.degree. F.- products attained from cracking of the residue.
U.S. Pat. No. 4,663,025 to Phillips as assignee of Fu is directed to a catalytic cracking process carried out in the presence of a zeolite which may be a partially dealuminated natural mordenite, a partially dealuminated synthetic faujasite, or a partially dealuminated synthetic mordenite. The zeolite has a unit cell size of 24.31A to 24.42A, a silicon to aluminum atom ratio in the framework of 8-21:1, and a surface area of 500-1000 m.sup.2 /g. The zeolite has been partially dealuminated by treating with steam at 1300.degree. F.-1500.degree. F. for 0.5-5 hours, followed by treatment with aqueous acid such as hydrochloric acid at 180.degree. F.-210.degree. F. for 1-10 hours.
It is an object of this invention to provide a process for treating a zeolite catalyst to yield a novel treated zeolite catalyst which is characterized by improved properties. Other objects will be apparent to those skilled in the art.